Indicating switch



NOV. 4, 1947. J, H, SCHELLMAN- l 2,430,189

INDICATING SWITCH Filed De'c. 22. A194:4

Patented Nov. 4, 1947 INDICATING SWITCH Joseph H. Schellman, Ridley Park, Pa., assigner to Robert Hetherington and Son, Inc., Wilmington, Del., a corporation of Delaware Application December 22, 1944, Serial No. 569,287

/ 7 Claims.

My invention relates to switches of a type used in signalling for service of an attendant and which finds one use in the so-called hostess switch for use by passengers in airplanes.

One purpose of the invention is to provide for an instant alarm at the time a switch button is pressed and a signal at a distance as well as indication at the switch, both maintained until the switch is reset.

A further purpose is to provide for a distant gong and `signal, the gong being rung momentarily only and the signal being maintained until the switch is reset, and a local indication of the fact that the signal has been given, which also is maintained until the signal is reset.

A further purpose is to provide a hill and valley plunger-type switch with a contact made by the plunger at the end of its operating stroke, and interrupted as soon as the pressure upon the switch button is released. An indicating light in the operating button shows when the switch has been pressed and that it has not yet been reset.

A further purpose is to energize the plunger of a switch through the contacts made and to maintain a light in a push botten by a spring connection from the plunger.

A further purpose is to operate a gong separately by overtravel of a switch plunger and to disconnect it when pressure on a switch-operating button is released.

Further purposes will appear in the specication and in the claims.

I have preferred to illustrate my invention by one form only, using a form which is practical, effective, simple and inexpensive, but which has been selected because it particularly well displays the advantage of the switch.

The ligure is a longitudinal, central section through my preferred form of switch.

The switch as illustrated is intended to be mounted upon a board or panel I by which one side of the circuit may be grounded.

The switch itself is protected by a metallic casing Il, inserted into the panel and held in place by a lock nut l2 pressing through a washer i3. The front end of the casing Il is flanged at `I4 and the body of the casing is reduced at I5.

The outer casing is bored at I6 to guide the' outer surface il of an operating slide I3. The casing is counterbored at I9 to form a guiding surface for' the flange '20 upon the slide. The flange engages shoulder 2| to limit forward movement. The bore is further counterbored at 22 to receive and. haldcueped insulation 2,3 restlng against the shoulder 24, and a rear block 25 of insulation within which terminals 25 and 26 are mounted.

The terminals are turned toward each other at 2l and 28 to form transversely directed contacts 29 and 30` which are connected when the circuit is closed, by the metallic iront plate 3| of a shuttle or shorting bar 32. The ends 33 of the front plate of the shorting bar are turned rearwardly at 34 to engage at their rear edges 35 with the front face 36 of insulation block 25. The side edges 3l of the rearwardly turned ends are inwardly turned at each end, toward each other and support an insulating rear plate 38 which lies substantially parallel to the front plate.

ln the front part of the slide I8 is mounted a lamp 39 which is inserted from the rear within a sleeve 4i) which is threaded into the front end of the body of the slide and is transversely flanged at 4I to engage the front of the slide.

The lamp shell 42 rests against a shoulder 43. The shell ts suiliciently tightly within the sleeve for the lamp to be held therein. In front of the lamp and attached to the sleeve is a translucent plastic press button 44.

One of the ends of the iilament of the lamp is grounded by the sleeve 4!) and the other end of the larnent is connected to a metal knob 45 supH ported at the rear of the lamp shell upon closure 46.

A spring 41 presses against knob 45 so as oontinuously to make electrical contact with it. The opposite end of the spring is wound about the front of hill and Valley plunger 48 so that the plunger forms an abutment for the spring. The plunger is mounted within insulation 4S by a collar 55. The insulation or the collar is pushed forward by a weak spring 5I, insuilicient to return to switch to open position. It pushes at the rear against cupped insulation 23 toward collar 50. The plunger carries hill and valley operating, oppositely facing, truncated cones 52, 53 havin-g abutting bases.

The cones are constricted by parallel spiral side springs 54 located between the front and rear plates of the shuttle or shorting bar.

The plunger passes through an opening 55 in the cupped insulation and is pressed normally forwardly by the weak spring 5l resting upon the transverse partition 55 of the cupped insulation at the rear or" the weak spring.

The splined connection of key 51 and slot 58 prevents relative rotation of the slide I8 within the casing, Good Contact is maintained between the slide and casing by a spring 59 upon the one engaging the other.

The rear end 60 of the plunger enters a recess 6l within the block insulation, at the bottom of which recess is a third terminal 62. This third terminal can be reached by the plunger when the press button is being pushed by the user. When pressure on the plunger is released the plunger immediately is slightly spaced from its contact with the terminal. This takes place when the parts are at rest in switch closed position, and is due to the pressure of the rear spiral spring when the user is not pushing on the button.

In use, one contact such as 26 is connected to the positive side of the current supply, and the other terminal to the device to be operated, and the connection passes through a pilot light or annunciator 63 upon the board at which the various calls are registered.

Since the plunger jumps to the position seen in the figure and stays there until the plunger is pulled forwardly to reset it, the pilot light stays on all the time until the switch or the annunciator is reset by hand, The contact 62, on the other hand, is connected through a gong 64 to ground and rings during such time only as the user 1s pressing the button. The light within the button is connected from the source through the spaced springs 54, plunger, spring lil, lament, sleeve and casing to ground upon the frame. It stays lighted during the entire time while the front of the shorting bar connects across from terminal 2l to terminal 28.

In assemblage:

The slide and all oi the switch parts having to do with the hill and valley mechanism are inserted within the outer casing from the rear of the casing, after which the slide and translucent button are put in from the front. The outer casing is then mounted upon a frame and is held in place by the nut and with the assistance of the washer.

Starting with the parts in the position seen in the :ligure and with the main terminals connected through from the positive line to the pilot light or annunciator and ground, with the third terminal connected with the coil of the gong and to ground and the outer casing grounded through the irame or panel, the operation is as follows:

The button is in its rear position in which the forward face-the longer face-of the truncated cone cam has just thrown the spaced spiral springs forwardly and the springs have carried with the shorting bar with them. The metallic front of the shorting bar has `iust engaged the transverse contacts. This closes the main circuit through the `pilot light or annunciator and at the same time energizes the metallic plunger, thus passing current through the light within the button. At substantially the same time the pressure upon the button pushes the plunger beyond the point at which the shorting bar is thrown and closes the rear end of the plunger against the third contact, the contact through which the gong is energized As soon as the pressure upon the button is released the rear spiral spring presses the slide forward sufficiently to open the contact through which the gong current passes, out without resetting the switch, which is later reset by hand by grasping the slide or the front button and pulling the slide forwardly to a position in which the hill and valley switch reverses the shorting bar, opening the circuit through the light button and opening the circuit across from the one transverse contact to the other.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a hostess switch, an outer casing, a slide unit Within the casing having a translucent front button, a lamp within the button, a hill and valley plunger carried by the unit and connections from the hill and valley plunger to one side of the lamp, the other side being grounded through the slide, a shorting bar operated by the hill and valley plunger, contacts engaged by the shorting bar, a spring pressing the plunger forwardly and of insuilicient strength to return the plunger when the button is released, and a supplemental contact engaged by the plunger when the button is pressed fully in and from which the plunger is separated by pressure of the spring when pressure on the button is released.

2. In a hostess switch, an outer casing, a slide movable in the easing, a spring pressing the slide forwardly, a hill and valley plunger carried by the slide, a shorting bar operated by the plunger, contacts engaged by the shorting bar, a supplemental contact engaged by the plunger when the button is pressed rearwardly on the same stroke in which the shorting bar is moved forwardly and a second spring releasing the plunger from the supplemen tal Contact when the button is released but insufficiently strong to return the plunger when the slide is released.

3. In a hostess switch, an outer casing adapted to be grounded through a mount, a slide unit movable within the casing, block insulation carried by the slide unit, a hill and valley plunger mounted in the insulation, rear block insulation in the casing, terminals carried by the rear block insulation, rearwardly facing cupped insulation between the two insulation blocks and surrounding the ends of the contacts of the terminals, a spring between the cupped insulation and the insulation block of the unit, a front lamp in the slide unit having one terminal adapted to be connected with the ground, a spring Within the unit electrically connecting the plunger and the other lamp terminal, a translucent button upon the front of the slide and a shorting bar operated by the hill and valley plunger to `ioin the connections of the terminals.

4. In a hostess switch, an outer casing adapted to be grounded through a mount, a slide unit movable within the casing, block insulation carried by the slide unit, a hill and valley plunger mounted in the insulation, rear block insulation in the casing, terminals carried by the rear block insulation, rearwardly facing cupped insulation between the two insulation blocks and surrounding the ends oi' the contacts of the terminals, a spring between the cupped insulation and the insulation block of the unit, a front lamp in the slide unit having one terminal adapted to be grounded, a spring within the unit connecting the plunger and the other lamp terminal, a translucent button upon the front of the slide and a shorting bar operated by the hill and valley plunger to join the connections of the terminals, and an additional contact engaged by the plunger when the plunger is pushed all the way in, the additional contact being adapted to energize another circuit, the spring between the cupped insulation and the insulation block being sufficiently strong to unseat the plunger from the additional contact but not strong enough to reverse the plunger and shorting bar.

5. A hostess switch comprising an electrically conducting outer casing, an electrically conducting slide member therein, spring means ensuring engagement between the casing and the slide member, a plunger carried by the slide, a lamp in the front of the slide, a translucent button at the end of the lamp, a spring connecting the plunger and one terminal of the lamp, the other terminal being grounded through the casing, insulation within the slide supporting the plunger, a switch closed by the plunger and having overthrow, and terminals for the switch engaged by the plunger when it overthrows.

6. In a hostess switch, an outer electrically conductingcasing, an electrically conducting slide within and having contact therewith, whereby the casing and slide can be grounded in a grounded mount, a sleeve within the slide and electrically connected with it, a lamp within the sleeve having one terminal connected to the sleeve, a button upon the front of the slide, means for showing the light of the lamp through the button, insulation within the rear of the sleeve, a plunger carried by the insulation, a spring providing and maintaining electrical connections between the plunger and the second terminal of the lamp, rear insulation for the casing, intermediate insulation within the casing, a spring pressing the intermediate and sleeve insulation apart, electrical connections having transverse terminals and carried by the rear insulation,

` a shorting bar engaging the terminals in one position and cam means for throwing the shorting bar reversely to the direction of throw of the plunger and a supplemental contact engaged by the plunger with overthrow of the plunger beyond the throw required for shifting the shorting bar, the spring between the intermediate and sleeve insulation being suliciently strong to break the connection to the supplemental contactbut insuillciently strong to reverse the shorting bar.

7. A hill and valley type plunger switch having a metallic outer casing adapted to be mounted upon a board, primary contacts, a metallic hill and valley plunger and a shorting bar, uniting the primary contacts electrically to each other and to the plunger, a spring tending to push the plunger forward and, a supplemental contact engaged by the plunger when its rearward plunger position is pushed rearwardly against the pressure of the spring on the same stroke in which the shorting bar is thrown forwardly, the spring being sufficiently strong to unseat the plunger from the supplemental contact but insufficiently strong to reverse the shorting bar.

JOSEPH H. SCHELLMAN.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,087,935 Batcheller July 27, 1937 2,109,054 Soring et al. Feb. 22, 1938 2,234,954 Bergman Mar. 18, 1941 1,871,748 Schramm Aug. 16, 1932 1,998,072 Blake et al. Apr. 16, 1935 2,217,526 Pelikan Oct. 8, 1940 2,216,671 McDonald, Jr. Oct. 1, 1940 2,374,873 McDonald, Jr. May 1, 1945 1,837,185 Jones Dec. 15, 1931 1,659,914 Haskel Feb. 21, 1928 2,109,790 Batcheller Mar. 1, 1938 

